This continuation application is for funds to enable the principal investigator to prepare a monograph on "Steroid-Protein Interactions". This book will be a continuation volume to a previous monograph of the same title which appeared in 1971. It will not repeat any of the material discussed in the first monograph, but will present a comprehensive and critical review of the results achieved since 1970 in many laboratories including that of the applicant. The emphasis will be on steroid interactions with serum proteins, but interactions with other steroid-binding proteins (intracellular receptors and other tissue proteins, enzymes, immunoglobulins) will be included to the extent as the results are sufficiently established from a biomedical and physicochemical viewpoint.